Technical Field
This disclosure relates generally to turbo-machinery rotor components which may form stress risers during operation. More specifically, this disclosure relates to turbo-machinery rotor components enhanced by laser shock peening and testing of the effectiveness of such laser shock peening.
Description of the Related Art
Turbo-machinery such as gas turbine engines and, in particular, aircraft gas turbine engines include compressors with rotors and rotor blades that operate at high rotational speeds that subject the rotor and rotor blades to very high stress fields. These rotor and rotor blades are designed to operate in high stress fields and often contain features that are stress risers which subject the components to fatigue failure and reduced operating life.
It is expensive to refurbish and/or replace rotors and rotor blades in a gas turbine engine and, therefore, any means to increase rotor and rotor blade life is very desirable. Therefore, it is highly desirable to design and construct longer lasting rotor and rotor blade components that are better able to resist both low and high cycle fatigue than present rotor and rotor blade components.
Laser shock peening (LSP) or laser peening generally increases the resistance of metals and alloys to fatigue. LSP does this by using a high energy pulsed laser to produce residual compressive stresses into the surface of a part treated with LSP. The residual compressive stresses from LSP extend deeper below the surface than those from shot peening, usually resulting in a significantly greater benefit in fatigue resistance after laser peening. LSP has been used to improve fatigue capability in compressor rotors and rotor blades as disclosed in U.S. Pat. No. 6,541,733.
Testing the effects of LSP and other material property improvement processes on various parts, such as compressor rotor blades, can be expensive as a single part may need to be tested at numerous places and at numerous depths. Often, multiple parts must be sacrificed to complete the testing, especially for components where reliability is critical, such as rotor blades for compressors of gas turbine engines, such as aircraft engines. Hence, methods for efficient but thorough testing of rotor blades are needed.